Abstract 916: Klotho-protein Regulates Transient Receptor Potential Canonical-1-mediated Ca(2+)-influx In Endothelial Cells And Prevents Cell Death And Disruption Of Endothelial Integrity Induced By Ca(2+)-overload

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Mitsuhiko Okigaki ◽  
Tetsurou Kusaba ◽  
Shoken Honsho ◽  
Akihiro Matsui ◽  
Shinsaku Matsunaga ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Calcification ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Peak Level ◽  
Vegf Receptor ◽  
Downstream Signaling ◽  
Klotho Protein ◽  
Deficient Mice

Introduction Klotho-deficient mice have extensive vascular calcification. However, the mechanism involved has not been elucidated. We analyzed the endothelial cells of Klotho-deficient mice (Klotho-ECs) and found a novel functional role for the Klotho-protein in the maintenance of vascular homeostasis. Methods and Results Primary-cultured endothelial cells from the aorta of wild-type- (WT) and Klotho- deficient mice were loaded with fura-2 and stimulated with VEGF. In WT-ECs, intracellular Ca(2+) concentration ([Ca(2+)]i) elevated to the peak level, and it decreased to the basal level in +5 minutes. Whereas, in Klotho-ECs, after similar peak level to WT-ECs, the elevation of [Ca(2+)]i was sustained at ~35% of the peak level for more than 10 minutes. In Ca(2+) free medium, this sustained elevation was abolished. Immunostaining revealed that, in Klotho-ECs, VEGF-induced co-internalization of the Ca(2+) channel; TRPC-1, with VEGF-receptor-2 (VEGFR-2) was abolished, thereby, at 30 minutes after VEGF-stimulation, expression levels of TRPC-1 in the plasmamembrane was 2.2-fold higher than in WT-ECs. Klotho-protein constitutively bound to VEGFR-2 and TRPC-1, strengthened their association, and promoted their co-internalization. VEGF-induced activation of Rac-1 and reorganization of F-actin, which are involved in internalization, were impaired in Klotho-ECs, and restored by the replacement of Klotho-protein. VEGF-induced phosphorylation of VEGFR-2 and its downstream signaling molecules, including Src, Akt, PLCγ, and Caveolin1, was attenuated. As the biological consequence of sustained increase in [Ca(2+)]i, activation of calpain and caspase-3 followed by apoptosis was promoted in Klotho-ECs in vivo and vitro. Also, expression of VE-cadherin in the plasmamembrane was reduced and intimal hyperpermeability was observed in the aorta of Klotho-deficient mice, which presumably lead to exudation of the Ca(2+)/phosphor -rich serum into the vessel walls, followed by extensive vascular calcification. Conclusion Thus, Klotho-protein regulates ligand-induced Ca(2+) influx and subsequent biological functions involved in vascular calcification.

Abstract 1287: TRPV4-Deficient Mice Exhibit Impaired Endothelium-Dependent Relaxation Induced by Acetylcholine in Vitro and in Vivo

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
David Zhang ◽  
Suelhem Mendoza ◽  
Aaron Bubolz ◽  
Makoto Suzuki ◽  
David Gutterman
Keyword(s):  
Blood Pressure ◽  
Endothelial Cells ◽  
Carotid Arteries ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Mice Model ◽  
Synthase Inhibitor

Agonist-induced Ca 2+ entry in endothelial cells is important for the synthesis and release of vasoactive factors, although mechanisms of Ca 2+ entry remain largely unknown. Emerging evidence suggests that the transient receptor potential vanilloid 4 (TRPV4) channel, a Ca 2+ -permeant TRP channel, is expressed in endothelial cells and may be involved in the regulation of vascular tone. Here we investigated the potential role of TRPV4 channels in acetylcholine-induced vasodilation in vitro and in vivo using the TRPV4 knockout (TRPV4 −/− ) mice model. Carotid arteries were isolated and preconstricted with the thromboxane A2 mimetic U46619. Concentration-dependent relaxations to acetylcholine (10 −9 –10 −5 M) were markedly reduced in carotids of TRPV4 −/− vs. wild-type (WT) mice (maximal relaxations of 31±12% vs 53±4%, respectively; n=4 mice). There was no significant change in the ED50 for Ach. In both WT and TRPV4 −/− , acetylcholine-induced relaxations were blocked and converted to constrictions by the NO synthase inhibitor L-NAME (maximal relaxations of −25±6% and −24±7%, respectively). There was no difference in papaverine-induced relaxations between WT and TRPV4 −/− mice (maximal relaxations of 93±3% vs. 90±3%, respectively). U46619 caused similar contractions in carotid arteries from those mice. We also compared in vivo vasodilator effects of acetylcholine by measuring changes in blood pressure in those animals. Intravenous administration of acetylcholine (15 ng/gm bolus) decreased blood pressure by 32±6 mmHg in WT mice (from 90±15 to 57±10 mmHg; n=6), whereas blood pressure was reduced by only 10 mmHg in TRPV4 −/− mice (from 67±6 to 56±4 mmHg; n=12). Acetylcholine caused similar reductions in heart rate in WT and TRPV4 −/− mice, with mean changes of 365±57 and 292±40 beats/min, respectively. We conclude that the endothelium-dependent vasodilator response to acetylcholine is reduced both in vitro and in vivo in TRPV4 −/− mice, and these findings may provide novel insight into the mechanisms of Ca 2+ entry evoked by chemical agonists in endothelial cells. The paradoxically lower baseline blood pressure in TRPV4 −/− mice requires further investigation.

scholarly journals TRPV1 and TRPA1 Channels Are Both Involved Downstream of Histamine-Induced Itch

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1166
Author(s):  
Jenny Wilzopolski ◽  
Manfred Kietzmann ◽  
Santosh K. Mishra ◽  
Holger Stark ◽  
Wolfgang Bäumer ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Signal Transmission ◽  
Receptor Potential ◽  
Histamine Receptor ◽  
Receptor Subtypes ◽  
Downstream Signaling ◽  
Transient Receptor ◽  
Induced Signal

Two histamine receptor subtypes (HR), namely H1R and H4R, are involved in the transmission of histamine-induced itch as key components. Although exact downstream signaling mechanisms are still elusive, transient receptor potential (TRP) ion channels play important roles in the sensation of histaminergic and non-histaminergic itch. The aim of this study was to investigate the involvement of TRPV1 and TRPA1 channels in the transmission of histaminergic itch. The potential of TRPV1 and TRPA1 inhibitors to modulate H1R- and H4R-induced signal transmission was tested in a scratching assay in mice in vivo as well as via Ca2+ imaging of murine sensory dorsal root ganglia (DRG) neurons in vitro. TRPV1 inhibition led to a reduction of H1R- and H4R- induced itch, whereas TRPA1 inhibition reduced H4R- but not H1R-induced itch. TRPV1 and TRPA1 inhibition resulted in a reduced Ca2+ influx into sensory neurons in vitro. In conclusion, these results indicate that both channels, TRPV1 and TRPA1, are involved in the transmission of histamine-induced pruritus.

scholarly journals The Role of TRPM2 in Endothelial Function and Dysfunction

2021 ◽  
Vol 22 (14) ◽  
pp. 7635
Author(s):  
Wioletta Zielińska ◽  
Jan Zabrzyński ◽  
Maciej Gagat ◽  
Alina Grzanka
Keyword(s):  
Endothelial Cells ◽  
Endothelial Function ◽  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Sequence Motif ◽  
Attractive Therapeutic Target ◽  
Transient Receptor

The transient receptor potential (TRP) melastatin-like subfamily member 2 (TRPM2) is a non-selective calcium-permeable cation channel. It is expressed by many mammalian tissues, including bone marrow, spleen, lungs, heart, liver, neutrophils, and endothelial cells. The best-known mechanism of TRPM2 activation is related to the binding of ADP-ribose to the nudix-box sequence motif (NUDT9-H) in the C-terminal domain of the channel. In cells, the production of ADP-ribose is a result of increased oxidative stress. In the context of endothelial function, TRPM2-dependent calcium influx seems to be particularly interesting as it participates in the regulation of barrier function, cell death, cell migration, and angiogenesis. Any impairments of these functions may result in endothelial dysfunction observed in such conditions as atherosclerosis or hypertension. Thus, TRPM2 seems to be an attractive therapeutic target for the conditions connected with the increased production of reactive oxygen species. However, before the application of TRPM2 inhibitors will be possible, some issues need to be resolved. The main issues are the lack of specificity, poor membrane permeabilization, and low stability in in vivo conditions. The article aims to summarize the latest findings on a role of TRPM2 in endothelial cells. We also show some future perspectives for the application of TRPM2 inhibitors in cardiovascular system diseases.

scholarly journals Transient receptor potential ankyrin 1 (TRPA1) receptor is involved in chronic arthritis: in vivo study using TRPA1-deficient mice

2016 ◽  
Vol 18 (1) ◽  
Author(s):  
Ádám Horváth ◽  
Valéria Tékus ◽  
Melinda Boros ◽  
Gábor Pozsgai ◽  
Bálint Botz ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Chronic Arthritis ◽  
In Vivo Study ◽  
Transient Receptor ◽  
Deficient Mice

scholarly journals Emerging Roles for Ion Channels in Ovarian Cancer: Pathomechanisms and Pharmacological Treatment

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 668
Author(s):  
Concetta Altamura ◽  
Maria Raffaella Greco ◽  
Maria Rosaria Carratù ◽  
Rosa Angela Cardone ◽  
Jean-François Desaphy
Keyword(s):  
Ovarian Cancer ◽  
Ion Channels ◽  
Transient Receptor Potential ◽  
Critical Role ◽  
Gynecologic Cancer ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Platinum Resistance

Ovarian cancer (OC) is the deadliest gynecologic cancer, due to late diagnosis, development of platinum resistance, and inadequate alternative therapy. It has been demonstrated that membrane ion channels play important roles in cancer processes, including cell proliferation, apoptosis, motility, and invasion. Here, we review the contribution of ion channels in the development and progression of OC, evaluating their potential in clinical management. Increased expression of voltage-gated and epithelial sodium channels has been detected in OC cells and tissues and shown to be involved in cancer proliferation and invasion. Potassium and calcium channels have been found to play a critical role in the control of cell cycle and in the resistance to apoptosis, promoting tumor growth and recurrence. Overexpression of chloride and transient receptor potential channels was found both in vitro and in vivo, supporting their contribution to OC. Furthermore, ion channels have been shown to influence the sensitivity of OC cells to neoplastic drugs, suggesting a critical role in chemotherapy resistance. The study of ion channels expression and function in OC can improve our understanding of pathophysiology and pave the way for identifying ion channels as potential targets for tumor diagnosis and treatment.

scholarly journals Linalool odor‐induced analgesia is triggered by TRPA1-independent pathway in mice

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Hideki Kashiwadani ◽  
Yurina Higa ◽  
Mitsutaka Sugimura ◽  
Tomoyuki Kuwaki
Keyword(s):  
Pain Threshold ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Analgesic Effects ◽  
Neuronal Mechanisms ◽  
Odor Exposure ◽  
Noxious Mechanical Stimulation ◽  
Transient Receptor ◽  
Deficient Mice

AbstractWe had recently reported that linalool odor exposure induced significant analgesic effects in mice and that the effects were disappeared in olfactory-deprived mice in which the olfactory epithelium was damaged, thus indicating that the effects were triggered by chemical senses evoked by linalool odor exposure. However, the peripheral neuronal mechanisms, including linalool receptors that contribute toward triggering the linalool odor-induced analgesia, still remain unexplored. In vitro studies have shown that the transient receptor potential ankyrin 1 (TRPA1) responded to linalool, thus raising the possibility that TRPA1 expressed on the trigeminal nerve terminal detects linalool odor inhaled into the nostril and triggers the analgesic effects. To address this hypothesis, we measured the behavioral pain threshold for noxious mechanical stimulation in TRPA1-deficient mice. In contrast to our expectation, we found a significant increase in the threshold after linalool odor exposure in TRPA1-deficient mice, indicating the analgesic effects of linalool odor even in TRPA1-deficient mice. Furthermore, intranasal application of TRPA1 selective antagonist did not alter the analgesic effect of linalool odor. These results showed that the linalool odor-induced analgesia was triggered by a TRPA1-independent pathway in mice.

scholarly journals A capsaicinoid-based soft drug, AG1529, for attenuating TRPV1-mediated histaminergic and inflammatory sensory neuron excitability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Magdalena Nikolaeva-Koleva ◽  
Laura Butron ◽  
Sara González-Rodríguez ◽  
Isabel Devesa ◽  
Pierluigi Valente ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Primary Cultures ◽  
Receptor Potential ◽  
Neuronal Firing ◽  
In Vivo Model ◽  
Drg Neurons ◽  
Trpv1 Channels ◽  
Soft Drug ◽  
Transient Receptor

AbstractTRPV1, a member of the transient receptor potential (TRP) family, is a nonselective calcium permeable ion channel gated by physical and chemical stimuli. In the skin, TRPV1 plays an important role in neurogenic inflammation, pain and pruritus associated to many dermatological diseases. Consequently, TRPV1 modulators could represent pharmacological tools to respond to important patient needs that still represent an unmet medical demand. Previously, we reported the design of capsaicinoid-based molecules that undergo dermal deactivation (soft drugs), thus preventing their long-term dermal accumulation. Here, we investigated the pharmacological properties of the lead antagonist, 2-((4-hydroxy-2-iodo-5-methoxybenzyl) amino)-2-oxoethyl dodecanoate (AG1529), on heterologously expressed human TRPV1 (hTRPV1), on nociceptor excitability and on an in vivo model of acute pruritus. We report that AG1529 competitively blocked capsaicin-evoked activation of hTRPV1 with micromolar potency, moderately affected pH-induced gating, and did not alter voltage- and heat-mediated responses. AG1529 displays modest receptor selectivity as it mildly blocked recombinant hTRPA1 and hTRPM8 channels. In primary cultures of rat dorsal root ganglion (DRG) neurons, AG1529 potently reduced capsaicin-evoked neuronal firing. AG1529 exhibited lower potency on pH-evoked TRPV1 firing, and TRPA1-elicited nociceptor excitability. Furthermore, AG1529 abolished histaminergic and inflammation mediated TRPV1 sensitization in primary cultures of DRG neurons. Noteworthy, dermal wiping of AG1529, either in an acetone-based formulation or in an anhydrous ointment, dose-dependently attenuated acute histaminergic itch in a rodent model. This cutaneous anti-pruritic effect was devoid of the normal nocifensive action evoked by the burning sensation of capsaicin. Taken together, these preclinical results unveil the mode of action of AG1529 on TRPV1 channels and substantiate the tenet that this capsaicinoid-based soft drug is a promising candidate for drug development as a topical anti-pruritic and anti-inflammatory medication.

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